America: the Vikings were there before Christopher Columbus

The Vikings ahead of Christopher Columbus. Known, this thesis is confirmed once again by Dutch scientists: they have managed to date precisely to the year 1021 the presence of Vikings on the North American continent, after their crossing of the Atlantic.

To this day, the only known site of the Viking occupation remains Anse aux Meadows, a bay in the far north of the island of Newfoundland, where the foundations of eight timber frame constructions remain. But as the study published in the British journal Nature On Wednesday, traditional carbon-14 dating from the past century is more than imprecise, spanning more than 250 years. However, everything indicates a brief and sporadic occupation of the place, according to archaeological remains and the “Sagas”, these semi-legendary texts narrating the epics of the Vikings.

The team led by Michael Dee and Margot Kuitems, respectively professor of isotope chronology and archaeologist at the Center for Isotopic Research at the Dutch University of Groningen, circumvented the obstacle with an original method. The Earth is constantly subjected to cosmic rays, “which continually produce carbon-14 (a heavier and much rarer form than the carbon atom) in the upper atmosphere”, Margot Kuitems told AFP.

This form of carbon goes “enter the carbon cycle, which is absorbed by plants through photosynthesisSometimes the radiation is much more powerful: these cosmic radiation “events” abruptly raise the level of carbon-14 in the atmosphere.

A Japanese study has isolated two such “events”, in 775 and in 993, the traces of which remain in trees whose age was well known. The sudden rise in carbon-14 was found on the dates in question in their growth rings, those circles that we see on a cut trunk and that help determine the age of the tree. Margot Kuitems’ team sought, using a mass spectrometer, the trace of the event of 993 in three samples of pieces of wood taken from the Anse aux Meadows site. Canadian experts had determined that these pieces had been worked there by the occupants with iron tools.

“When we measured the carbon-14 concentration in a series of dark circles, we found a sharp rise on one of them, and we were sure then that it corresponded to the year 993”, says the scientist. It was then enough to count the number of rings between the ring of “the cosmic event ” and the last one before the bark, to determine when the tree was felled. Answer: the year 1021. The measure worked for two pieces of wood, of which scientists were even able to specify that one belonged to a tree felled in the spring, and the other in the summer-autumn.